After the success of the file servers from IBM, Novell & SUN, many companies started to invest in research & development of dedicated file servers, but as usual one always becomes the first, Yes it was 3Com that succeeded in developing dedicated NAS “Network Attached Storage” and then the development continued in terms of product, protocol and features.
Network Attached Storage also called as NAS, is an intelligent storage box that connects directly to the network or home router. The box is managed logically that helps to store data with redundancy viz.a.viz RAID. It does not need fully functional operating system but is configured on network using the browser.
In general practice, the NAS is dedicated to the file sharing & does not provide the server centric activities so allows to add more storage to network without effecting the server operations. The NAS “Network Attached Storage” helps in segregating the server from storage hence the NAS “Network Attached Storage” units can be independently added to the network anywhere without effecting the operation.
As NAS “Network Attached Storage” does not need full featured operating system, we can use several open source software’s like FreeNAS that is available in 21 languages developed by iXsystems. A NAS system contains more than one hard disk arranged in RAID form. NAS “Network Attached Storage” provides storage as well as file systems & appears to the client as file server.
The popular protocols used by NAS are NFS (Network File System) on Unix Systems, SMB (server Message Block)/CIFS with windows operating system etc.
The unique type of NAS called as clustered NAS uses distributed file system running on several servers, hence has the ability to distribute data/meta data across nodes and storage devices.
The widely use NAS manufacturers are Agami Systems, Apple Inc., Dell, IBM, info trend, Netgear etc.